![]() Here the semiconductor device i.e., the thyristor is turned off by using either line, load, or forced commutation. The voltage and frequency of the signal obtained are of variable nature. The applied input is a fixed dc voltage that can be obtained from batteries but the output obtained is variable ac voltage. The devices that are designed to convert the dc signal into ac signal are known as inverters. Some major uses of choppers are in dc drives, SMPS, subway cars, electric traction, trolley trucks, vehicles powered by battery, etc. Generally, in low power circuits power transistors are used while in high power circuits thyristors are used.Ĭhoppers are classified on the basis of the type of commutation applied to them and on the basis of the direction of power flow. Here forced commutation is required to turn off the semiconductor device. The output is controlled by a low power signal that controls these semiconductor devices from a control unit. Generally, power transistors, MOSFETs, and thyristors are the semiconductor devices used for their fabrication. Here the achieved output dc voltage may have a different amplitude than the source voltage. The converters that convert the dc signal of fixed frequency present at the input into a variable dc signal at the output are also known as choppers. Its major applications are in dc drives, HVDC systems, compensators, metallurgical and chemical industries as well as in excitation systems for synchronous machines. Similar to diode rectifiers, here also the applied ac signal can be a single-phase or three-phase ac signal. Here line voltage operates the rectifier hence these are sometimes known as line commutated ac to dc converters. ![]() Phase Controlled Rectifiers: Unlike diode rectifiers, phase-controlled rectifiers are designed to convert a fixed value of ac signal voltage into a variable dc voltage. These are also used in welding and UPS related services. These are mainly used in electric traction and in electrochemical processes like electroplating along with in battery charging and power supply. Either a single-phase or three-phase ac signal is applied at the input. We have already learned in basic electronics that the devices that convert the AC signal into DC signal are known as rectifiers.ĪC to DC Converter is further classified as:ĭiode Rectifiers: This rectifier circuit changes applied ac input voltage into a fixed dc voltage. AC to DC ConvertersĪ type of converter that changes input AC signal into a DC is known as AC to DC converter. Let us now understand each type separately. The classification of power converters are as follows: Generally, inductors and capacitors exhibit negligible power loss characteristics in comparison to resistors. Power electronic switches have solid-state devices with components like inductors and capacitors. Static Power converters execute power conversion quite efficiently. But we can reduce harmonics to some extent using a simple low pass LC filter. ![]() ![]() In a general way, it is said that getting an absolutely clear signal is impossible. Signal conditioning offers signals of the pure form i.e., free from harmonics. A power electronic converter is composed of power semiconductor devices controlled by integrated circuits.Īn important aspect of converters is signal conditioning. We have already discussed that power electronic devices are a combination of converter and controller where the converter functions according to the control signal generated by the controller. This conversion of energy provides voltage and current in such a form that suits various user requirements. In our previous content, we have discussed that power electronic technology handles the controlling process of conversion of one form of electric energy into another form.
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